1. Field of the Invention
The invention relates to a switch, more particularly to a rolling-ball switch that is mounted on a circuit board for changing between OFF and ON states.
2. Description of the Related Art
Referring to FIG. 1, a conventional electrical tilt switch 10, as disclosed in U.S. Pat. No. 5,332,876, includes a conductive housing 11 having an open end 111 and a closed end 112, a conductive large ball 12 and a conductive small ball 13 disposed within the housing 11, a cap 14 covering the open end 111 of the housing 11, an electrical connector 15 inserted through the cap 14 and extending into the housing 11, and a terminal 16 fixed to the closed end 112 of the housing 11.
In operation, when the electrical tilt switch 10 is perpendicular relative to a reference horizontal surface (not shown) or only slightly tilted from this perpendicular position, the small and large balls 13, 12 roll toward the electrical connector 15 by gravity, so that the small ball 13 contacts electrically the electrical connector 15 and the housing 11, thereby placing the switch 10 in an ON state. At this time, the large ball 12 is in contact with the small ball 13 so as to press the small ball 13 against the electrical connector 15. When the large and small balls 12, 13 are rolled toward the closed end 112 of the housing 11 (as a result of the electrical tilt switch 10 being sufficiently tilted), the electrical tilt switch 10 is switched to an OFF state.
Another conventional electrical tilt switch, as disclosed in U.S. Pat. No. 5,209,343, includes a conductive housing having a substantially tubular jacket and one open end, a dielectric end cap member covering the open end of the housing, a plurality of conductive balls positioned within the housing, and a terminal connected to the housing.
Although each of the aforementioned conventional electrical tilt switches 10 can achieve its intended purpose, each of the aforementioned electrical tilt switches 10 can be placed in the ON state only when tilted in one direction. In some applications, it would be desirable for the electrical tilt switch to turn on when tilted in more than one direction.